Material Nature of the Brain (Coyne)

Human decision-making is governed by principles of biology and physics, denying the existence of free will and proving determinism.

Jerry Coyne (Professor, Department of Ecology and Evolution, University of Chicago). “Why You Don’t Really Have Free Will.” USAToday. January 1, 2012.

The first is simple: we are biological creatures, collections of molecules that must obey the laws of physics. All the success of science rests on the regularity of those laws, which determine the behavior of every molecule in the universe. Those molecules, of course, also make up your brain — the organ that does the "choosing." And the neurons and molecules in your brain are the product of both your genes and your environment, an environment including the other people we deal with. Memories, for example, are nothing more than structural and chemical changes in your brain cells. Everything that you think, say, or do, must come down to molecules and physics. True "free will," then, would require us to somehow step outside of our brain's structure and modify how it works. Science hasn't shown any way we can do this because "we" are simply constructs of our brain. We can't impose a nebulous "will" on the inputs to our brain that can affect its output of decisions and actions, any more than a programmed computer can somehow reach inside itself and change its program.

For example, by utilizing functional magnetic resonance imaging (fMRI), researchers are able to observe which areas of the brain are active as participants engage in experimental tasks. In one study by Greene, Nystrom, Engell, Darley, and Cohen (2004), participants were scanned while making difficult moral decisions. Greene and his colleagues found that the neural activation varied systematically depending on whether the dilemma was of a personal or impersonal nature. Additionally, depending on the relative activation of the brain centers associated with “cognitive” and “emotional” processing, one could make relatively accurate predictions as to how the participants would respond to the questions being posed. Another experiment by Huettel, Stowe, Gordon, Warner, and Platt (2006) found that differential levels of activation within the lateral prefrontal cortex during a gambling task could predict participants’ preferences for risk taking and general behavioral impulsiveness. Looking at studies like these, it seems evident that the neural activations researchers are detecting have a causal relationship with the behavior being observed. It also seems clear that it is not an immaterial “soul” that is at work during the decision-making processes, but a very material brain. Furthermore, it is hard to imagine a task that would be more under the “soul’s” jurisdiction than solving a moral dilemma. If the brain is at work solving even this most sacred problem, chances are good (and research points to the conclusion) that the brain is, in fact, in charge of all of our cognitive function.

As was previously illustrated,fMRI studies have already begun to elucidate the mechanisms by which our brains make decisions, and faster, more accurate technology is sure to arrive in the near future. Other studies have shown even more direct evidence thatour feelings of free will are illusory. Libet [et al], Gleason, Wright, and Pearl (1983)published a series of landmark and controversialexperiments in which participants indicated when they had come to the conscious decision to execute spontaneous, voluntarymovements. This time was compared to the onset of the “readiness potential” associated with the preparationof motor activity, asrecorded by electrodes on the scalp. Libet et al. concluded that participants were not conscious of their decisions to make movements until several hundred milliseconds after the first related cortical activity was detected. While the methods of this experiment have been questioned,more recent follow-upstudies (Lau, Rogers, & Passingham, 2006; Lau, Rogers, & Passingham, 2007)have shown similar findings[.], indicating that our brains know that we are going to move before “we” do.